rebase with MR 76

Documentation/Examples/CMakeLists.txt

@@ -108,7 +108,6 @@ target_link_libraries (vertical_EAS SuperStupidStack CORSIKAunits
 install (TARGETS vertical_EAS DESTINATION share/examples)
 CORSIKA_ADD_TEST (vertical_EAS)
 
-
 add_executable (staticsequence_example staticsequence_example.cc)
 target_compile_options(staticsequence_example PRIVATE -g) # do not skip asserts
 target_link_libraries (staticsequence_example

Framework/Cascade/Cascade.h

@@ -54,7 +54,6 @@ namespace corsika::cascade {
    * <code>auto GetTrack(Particle const& p)</auto>,
    * with the return type <code>geometry::Trajectory<corsika::geometry::Line>
    * </code>
-   *
    * <b>TProcessList</b> must be a ProcessSequence.   *
    * <b>Stack</b> is the storage object for particle data, i.e. with
    * Particle class type <code>Stack::ParticleType</code>
@@ -221,6 +220,18 @@ namespace corsika::cascade {
       setup::StackView secondaries(vParticle);
       [[maybe_unused]] auto projectile = secondaries.GetProjectile();
 
+      /*
+        Create SecondaryView object on Stack. The data container
+        remains untouched and identical, and 'projectil' is identical
+        to 'vParticle' above this line. However,
+        projectil.AddSecondaries populate the SecondaryView, which can
+        then be used afterwards for further processing. Thus: it is
+        important to use projectle (and not vParticle) for Interaction,
+        and Decay!
+       */
+      setup::StackView secondaries(vParticle);
+      [[maybe_unused]] auto projectile = secondaries.GetProjectile();
+
       if (min_distance < distance_max) { // interaction to happen within geometric limit
         // check whether decay or interaction limits this step
 

Framework/ProcessSequence/ProcessSequence.h

@@ -118,6 +118,20 @@ namespace corsika::process {
       return ret;
     }
 
+    template <typename TSecondaries>
+    EProcessReturn DoSecondaries(TSecondaries& vS) {
+      EProcessReturn ret = EProcessReturn::eOk;
+      if constexpr (std::is_base_of<SecondariesProcess<T1type>, T1type>::value ||
+                    is_process_sequence<T1>::value) {
+        ret |= A.DoSecondaries(vS);
+      }
+      if constexpr (std::is_base_of<SecondariesProcess<T2type>, T2type>::value ||
+                    is_process_sequence<T2>::value) {
+        ret |= B.DoSecondaries(vS);
+      }
+      return ret;
+    }
+
     template <typename TParticle, typename TTrack>
     corsika::units::si::LengthType MaxStepLength(TParticle& vP, TTrack& vTrack) {
       corsika::units::si::LengthType